Starting device for electric motors.



P. DUNNING.

STARTING DEVICE FOR ELECTRIC MOTORS.

APPLICATION FILED JUNE 27, 1911.

Patented Nov. 4, 1913.

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STARTINGYDEVIGE FOR ELECTRIC MOTORS.

APPLICATION FILED JUNE 27, 1911.

Patented N0v'.4,1913.

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P. DUNNING.

STARTING DEVICE FOR ELECTRIC MOTORS.

APPLICATION FILED JUNE 27, 1911.

Patented Nov. 4, 1913.

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Witnesses: Inventor His Attorney.

v 5 3 Parker Dunning 1 W Toall whom it may concern:

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UNITED STATES PATENT orrros. rams: murmur, tor sonmmcumr, ssienonnro sauna-AI Etno'rmc OOMBANY, A @COBBQBATLQN'DF NEW Y0 .K-

Summa io c Latte" l t nt- Potented NOVA, 1913.

Application med June :7, 1m. sem s. 685,576.

Be it known that I P KER Durante, a citizen of the United States, residing at- Schenectady, in the countyof Schenectady, State of'New York, have invented certain new and useful improvements in Starting Devices for. Electric Motors, of h h thefollowing i541 specification.

This invention relates to starting devices for electric motors and has for its ObJOCt the provision of an improved device of. this character in which the motor may be started and brought up to running s ed in a simple and reliable manner .upon t e closing of a control switch.

My invention relates more specifically to improvements in the type .of. switch in w ich the controllingjmember has two operative positions and an. ofi positiomthe latter position being between the operative positions.

In my previous Patent No. 970,478 I have described and claimed a starting switch to which my invention isparticularly applicalimited in its application to this particular type of switch. In the switch described in the said patent the motor first connected to the line through a transformer and then connected directly to the 'line- This is done by first moving the operating handle, which is spring pressed or biased toward the off PQS ti n, in one direction from the off POSltion to a starting position and then quickly; reversing the handle back through theoff position to a running position. In carrying out my present invention I provide means whereby the operation of this switch takes place automatically upon the -010 S1I1g of a control circuit, as ,for inst nce. by means of a pressure gage .or a float switch. I also provide means whereby the running connections :are not made until the motor reaches asuitablespeed.

Other Objects and purposes of my invention will appear in the course of .the following specificati n in which I have shown my invention embodied in concrete form for P p of ustration.

"In the accompanying drawings lllustrating my invention, 1 1s a front view of a motorsstanting panel embody ng mv invention; Fi 2 .is .a side elevation of the same with die casing partly .broken awe to show the construction o f the switc proper; Fig. .3 is ,a view similar to Fig. 1

I with the parts shown in the starting position; 4 is a similar view with the parts in running position; Fig. 5 is a diagram of the circuit connections.

Referring first to 'F ig. 2, it will be seen that the switch proper 10 'is inclosedin an iron casing mounted u on the back of the slate or marble panel 11 The specific construction of this switch 10 forms no part of my present invention, since it is covered by my previous patent above referred to. So far as the operation of this switch is concerned, it need only ,be said here that the shaft 12 is spring pressed to a central or off sition in which all of the contacts operate b the shaft are in inoperative position. This shaft is first rotated in a clockwise direction to connect the motor to .the line through a transformer and then rotated in a counterclockwise direction back through the OE position to runnin position to connect the motor direct to the 'ne. The

type of transformer employed in this case ble, although it is obvious that it is not...

is that known as an.-autotransformer or compensator 13 located in the upper part of the casing 10 and the switch contacts 1d are located in the lower art of the casing.

By reference to "ig'. 5 it will be seen that there are ten movable contacts 14 cooperatin with nine fixed. contacts. When the sha 12 'is rotated in a clockwise direction, the lower set of moving and fixed contacts in Fig. 5 marked Starting are moved into engagement so that the current from the line, which in this case is a three phase circuit, passes through .the transformer 13 and thence. to the motor M. This increases the current so as to give a sufiicient starting torque with a corresponding decrease in the voltage applied to the motor. When the shaft is rotated in the opposite direction the contacts marked Running are moved into en agement so that the motor is connected direct to the line. In Fig. 5. the shaft. 12 and contacts connected therewith are represented in a diagrammatic way to show the circuit connections, the shaft being shown in the plane,

17 is mounted on the end of the shaft 12 and is provided at its ends with plungers 18 and 19 coiiperating with the coils l5 and 16 respectively. \Vhen the winding 16 is energized, the core 19 will be drawn downward and the shaft 12 rotated in a clockwise direction to connect the motor to the line through the transformer. WVhen the coil 15 is energized the core 18 isdrawn downward to rotate the shaft 12 in a counterclockwise direction to connect the motor direct to the line. The terminals of the two coils 15 and 16 are connected together at the point 20 and the other two terminals are connected with the studs 21 and 22. A pivoted switch arm 23 is arranged to move into engagement with the contact 21 to energize coil 16 and to move into engagement with contact 22 so as to energize coil 15. The common connection 20 of the two coils is connected with the pivotal point 24 of a switch 25, which is normally closed, as shown in Fig. 5, and is adapted to be opened by a lever 26 pivoted at 27. Secured to the shaft adjacent the arm 17 is a segmental plate 28 which is adaptedto be rotated when the shaft 12 is rotated. The edge of this plate is. di-

' rectly under the lever 26 and a lug -29 pivoted to the lever engages the edge of the plate. This edge is formed on an arc of a circle of which the shaft 12 is the center,

and a portion of the edge is formed upon a smaller radius so as to form a shoulder at 3O. The lever 26 is cut away at 31 so as to permit the lugto move up into the cut away portion as shown in Fig. 5, thereby permitting the lever to drop lower for reasons hereinafter described. Projecting downward from the lever 26 is a finger 32 which engages a segmental'projection 33 in certain positions so as to lift the lever. This projection is secured to the plate 28 and is likewisecut away as shown to form a shoulder at 34:. Resting upon the lever 26 i a rod 35 having an enlarged central portion 36 which forms a core for the winding 37. The upper end of this rod is connected with the switch arm 23 so as to move it into engagement with the stud 21. One end of the lever 26 engages with the switch 25while the opposite end is engaged by the core 38 of a no-voltage magnet 391 Two overload switches 40 are connected in two of the winding 16. The windin magnet 39 will immediately be raised and a circuit will be established for the wind ing 16 as follows (Fig. 5): from the main A through the float switch and conductor 42, switch 25, winding 16, contact 21, switch arm 23, through the conductor 43, overload switch 40 back through the float switch contacts to the main B. This causes the parts to assume the position shown in Fig. 3. In this position the shaft 12 and the plate 28 have been rotated to the right so that the lug 29 which is in engagement with the edge of the plate and supports the lever 26 has dropped down at the shoulder 30, the finger 32'resting upon the projection 33. This removes the support from the rod 35 but the latter has not dropped, as shown in Fig. 3, since it is held up by the winding 37. This movement of the shaft 12 makes the starting connections for the motor, that is, the motor is connected to the line through the autotransformer. This motor, which is of the squirrel cage type, takes a very large current at starting, three or four times the normal running current. This current is supplied through the autotransformer and traverses the winding 37 which is wound to hold up the rod 35 until the current is reduced by the speeding up of the motor. When the motor has reached a suitable speed so as to properly reduce the current, the rod 35 is released by the winding 37 and is permitted to drop into engagement with the lever 26. This causes the switch arm 23 to leave contact 21, and assume a position between the two contacts, thereby opening the circuit 16 being deenergized, the shaft 12 imme iately returns to the off position in response to its bias, carrying with it the plate 28. As the plate turns to the leftfrom the startin position (Fig. 3) it turns the lug 29 upward into the cut away portion 31, as shown in Fig. 5. When, however, the plate is rotated to the OE position shown in Fig. 5, the finger 32 drops down the projection 34 and permits the lever to be dropped, thereby causing the switch 23 to drop and engage with contact 22. This causes the winding 15 to be energized through conductor 42, switch 25 winding 15, contact 22, switch 23, and back to main B. The winding 15 being energized, the shaft 12'and plate 28 are caused to continue the movement in a counterclockwise direction through the off position to running position shown in Fig.

that the finger 32 has passed off of the projection 33. The dropping of the lever 26 causes the switch 25 to be opened, thereby opening the circuit of the winding 15. The

parts, however, do not return to the of! position, since they are mechanically locked in running position. mally running, with the transformer cut out of circuit. On failure of voltage from any cause, the core 38 will drop, thereby rotating the lever 26 to the position shown in Fig. 1, and the parts will return to-the position shown in this figure. The same will occur upon the occurrence of overload, since the no-voltage magnet will then be de-' energized.

It will be seen that I have provided a simple and reliable arrangement for automatically starting a motor and bringing it up to running speed, and whi1e I have described my invention as embodied in concrete form and as operating in a specific manner in accordance with the requirements of the patent statutes, it should be understood thatTdo not limit my invention thereto since various modifications thereof will suggest themselves to those skilled in the art without departing from the spirit of my invention, the scope of which is mt forth in the annexed claims.

What I claim as new, and desire to secure by Letters Patent of the'United States, is,

1. A starting device for electric motors comprising a switch member having a starting, a running and an ofl position and biasedto the oif position, and electrically controlled means for moving the member to starting releasing it when the current in the motor circuit reaches a predetermined value, and then moving it to running position.

. 2. A starting device for electric motors comprising a switch member biased to an ofi motor circuit position between the starting and the running position, and electrically controlled means for moving the member. to starting.

position, releasing it when the current in the value, and then moving it to running position. Y

3. A starting device for electric motors I comprising a switch member biased to an off position between the starting and the running position, electromagnetic means for moving the member to starting position, means controlled by the current in the motor circuit for denergizing said electromagnetic means to allow the switch member to return ,to of! position, and electromagnetic means arranged to be energized after the member leaves the starting position to move it to running position.

. A starting device for electric motors comprising a transformer, a switch member having an off position between two operative positions, electromagnetic means for-- moving the member to one operative position .to connect the motor to the line through the transformer, means controlled" by the our- The motor is now nor-.

drops to a predeterminedrent in the motor circuit for deenergizing said electromagnetic means to allow the switch member to-returnto off osition, and electromagnetic means arrange to be one gized after the member leaves starting position to move it to runnin position.

5. A starting device or electric motors comprising a switch member biased to an ofi position between the starting and the run.'

ning positions, electrically controlled means for movin the member to starting position releasing it after a predetermined interval and then moving it, to running position, and means for mechanically locking the member in running position.

6. A starting device for electric motors comprising a switch member biased to an ofi position between the starting and the run-. ning pos tions, two actuating windings one for moving the member to each osition against the bias, a switch controlle by the current in the motor circuit for controlling the circuits of said windings, and means whereby said switch is o erated by the move ment of the switch mem r.

7. A starting device for electric motors comprising a switch member biased to an oi! position between the starting and'the running posit-ions, two actuating windings one for moving the member to each position against the bias, a switch for energizing either of said windings and biased to energize the running winding, a mechanical connection between the member and the switch for moving the latter to energize the starting windin in certain positions of the member and re ease it 'in other-positions, and means for retarding the movement of the switch in response to its bias.

8. A starting device for electric motors comprising a switch member biased to an off position between the starting and the rum ning positions, two actuating windings one for moving the member to each position against, the bias, a switch for energizing either of said windings and biased to energize the running winding, a mechanical con-. nection between the member and the switch for moving the latter to energize the starting winding when the member returns from the running to the ofi position but does not actuate the switch when moving from the starting to the off position.

' 9. A starting device for electric motors comprising a switch member biased to an on position between the starting and the runningpositions, two actuating windings one for movin the member to each position against the bias, a switch for energizing either of said windings and biased to energize therunning winding, and means whereby 'the switch, 18 moved to closed position against its bias when themember is moved in one direction but not when it moves in the opposite direction, the movement of said switch in response to its bias being under the control of the current in the motor circuit;

10. A starting device for electric motors comprising a switch member biased to an ofi position between the starting and the running positions, electromagnetic means for moving the member to each position against the bias, a switch operated by said member for controlling said electromagnetic means, and a winding in the motor circuit for controlling the movement of the switch. 11. A starting device for electric motors comprising a switch member biased to an off position between the startin and running positions, two actuating windings for moving the member to each position against the bias, a switch for energizing either of said windings and biased to energize the running winding, an element movable upon the movement of said switch member to either hoid said switch in operative position against the bias and hold it in an intermediate position or release it, and means respon-' sive to current in the motor circuit for conleased.

12. A starting device for electric motors either hold said switch in operative position or release it, means responsive to current in the motor circult for controlhn the move- .ment of the switch when release and means associated with said element for locking the switch member in running position, and means for releasing said member upon failure of voltage.

In witness whereof, I have hereunto set my hand this 24th day of June, 1911;

I PARKER DUNNING. Vfitnesses:

BENJAMIN B. HULL, MARGARET E. WooriLnr,

trolling themovement of the switch when re- 

